busybox: add upstream security fixes

CVE-2017-15873: Integer overflow in decompress_bunzip2.c leads to a read
access violation

CVE-2017-15874: Integer overflow in decompress_unlzma.c leads to a read
access violation

Cc: Adam Duskett <aduskett@gmail.com>
Signed-off-by: Baruch Siach <baruch@tkos.co.il>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>

package/busybox/0006-bunzip2-fix-runCnt-overflow-from-bug-10431.patch

@@ -0,0 +1,101 @@
+From 0402cb32df015d9372578e3db27db47b33d5c7b0 Mon Sep 17 00:00:00 2001
+From: Denys Vlasenko <vda.linux@googlemail.com>
+Date: Sun, 22 Oct 2017 18:23:23 +0200
+Subject: [PATCH] bunzip2: fix runCnt overflow from bug 10431
+
+This particular corrupted file can be dealth with by using "unsigned".
+If there will be cases where it genuinely overflows, there is a disabled
+code to deal with that too.
+
+function                                             old     new   delta
+get_next_block                                      1678    1667     -11
+
+Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
+Signed-off-by: Baruch Siach <baruch@tkos.co.il>
+---
+Patch status: upstream commit 0402cb32df0
+
+ archival/libarchive/decompress_bunzip2.c | 30 +++++++++++++++++++-----------
+ 1 file changed, 19 insertions(+), 11 deletions(-)
+
+diff --git a/archival/libarchive/decompress_bunzip2.c b/archival/libarchive/decompress_bunzip2.c
+index 7cd18f5ed4cf..bec89edd3a4d 100644
+--- a/archival/libarchive/decompress_bunzip2.c
++++ b/archival/libarchive/decompress_bunzip2.c
+@@ -156,15 +156,15 @@ static unsigned get_bits(bunzip_data *bd, int bits_wanted)
+ static int get_next_block(bunzip_data *bd)
+ {
+ 	struct group_data *hufGroup;
+-	int dbufCount, dbufSize, groupCount, *base, *limit, selector,
+-		i, j, runPos, symCount, symTotal, nSelectors, byteCount[256];
+-	int runCnt = runCnt; /* for compiler */
++	int groupCount, *base, *limit, selector,
++		i, j, symCount, symTotal, nSelectors, byteCount[256];
+ 	uint8_t uc, symToByte[256], mtfSymbol[256], *selectors;
+ 	uint32_t *dbuf;
+ 	unsigned origPtr, t;
++	unsigned dbufCount, runPos;
++	unsigned runCnt = runCnt; /* for compiler */
+ 
+ 	dbuf = bd->dbuf;
+-	dbufSize = bd->dbufSize;
+ 	selectors = bd->selectors;
+ 
+ /* In bbox, we are ok with aborting through setjmp which is set up in start_bunzip */
+@@ -187,7 +187,7 @@ static int get_next_block(bunzip_data *bd)
+ 	   it didn't actually work. */
+ 	if (get_bits(bd, 1)) return RETVAL_OBSOLETE_INPUT;
+ 	origPtr = get_bits(bd, 24);
+-	if ((int)origPtr > dbufSize) return RETVAL_DATA_ERROR;
++	if (origPtr > bd->dbufSize) return RETVAL_DATA_ERROR;
+ 
+ 	/* mapping table: if some byte values are never used (encoding things
+ 	   like ascii text), the compression code removes the gaps to have fewer
+@@ -435,7 +435,14 @@ static int get_next_block(bunzip_data *bd)
+ 			   symbols, but a run of length 0 doesn't mean anything in this
+ 			   context).  Thus space is saved. */
+ 			runCnt += (runPos << nextSym); /* +runPos if RUNA; +2*runPos if RUNB */
+-			if (runPos < dbufSize) runPos <<= 1;
++//The 32-bit overflow of runCnt wasn't yet seen, but probably can happen.
++//This would be the fix (catches too large count way before it can overflow):
++//			if (runCnt > bd->dbufSize) {
++//				dbg("runCnt:%u > dbufSize:%u RETVAL_DATA_ERROR",
++//						runCnt, bd->dbufSize);
++//				return RETVAL_DATA_ERROR;
++//			}
++			if (runPos < bd->dbufSize) runPos <<= 1;
+ 			goto end_of_huffman_loop;
+ 		}
+ 
+@@ -445,14 +452,15 @@ static int get_next_block(bunzip_data *bd)
+ 		   literal used is the one at the head of the mtfSymbol array.) */
+ 		if (runPos != 0) {
+ 			uint8_t tmp_byte;
+-			if (dbufCount + runCnt > dbufSize) {
+-				dbg("dbufCount:%d+runCnt:%d %d > dbufSize:%d RETVAL_DATA_ERROR",
+-						dbufCount, runCnt, dbufCount + runCnt, dbufSize);
++			if (dbufCount + runCnt > bd->dbufSize) {
++				dbg("dbufCount:%u+runCnt:%u %u > dbufSize:%u RETVAL_DATA_ERROR",
++						dbufCount, runCnt, dbufCount + runCnt, bd->dbufSize);
+ 				return RETVAL_DATA_ERROR;
+ 			}
+ 			tmp_byte = symToByte[mtfSymbol[0]];
+ 			byteCount[tmp_byte] += runCnt;
+-			while (--runCnt >= 0) dbuf[dbufCount++] = (uint32_t)tmp_byte;
++			while ((int)--runCnt >= 0)
++				dbuf[dbufCount++] = (uint32_t)tmp_byte;
+ 			runPos = 0;
+ 		}
+ 
+@@ -466,7 +474,7 @@ static int get_next_block(bunzip_data *bd)
+ 		   first symbol in the mtf array, position 0, would have been handled
+ 		   as part of a run above.  Therefore 1 unused mtf position minus
+ 		   2 non-literal nextSym values equals -1.) */
+-		if (dbufCount >= dbufSize) return RETVAL_DATA_ERROR;
++		if (dbufCount >= bd->dbufSize) return RETVAL_DATA_ERROR;
+ 		i = nextSym - 1;
+ 		uc = mtfSymbol[i];
+ 
+-- 
+2.15.1
+

package/busybox/0007-unlzma-fix-SEGV-closes-10436.patch

@@ -0,0 +1,34 @@
+From 9ac42c500586fa5f10a1f6d22c3f797df11b1f6b Mon Sep 17 00:00:00 2001
+From: Denys Vlasenko <vda.linux@googlemail.com>
+Date: Fri, 27 Oct 2017 15:37:03 +0200
+Subject: [PATCH] unlzma: fix SEGV, closes 10436
+
+Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
+Signed-off-by: Baruch Siach <baruch@tkos.co.il>
+---
+Patch status: upstream commit 9ac42c500586f
+
+ archival/libarchive/decompress_unlzma.c | 6 +++++-
+ 1 file changed, 5 insertions(+), 1 deletion(-)
+
+diff --git a/archival/libarchive/decompress_unlzma.c b/archival/libarchive/decompress_unlzma.c
+index a9040877efa0..be4342414435 100644
+--- a/archival/libarchive/decompress_unlzma.c
++++ b/archival/libarchive/decompress_unlzma.c
+@@ -450,8 +450,12 @@ unpack_lzma_stream(transformer_state_t *xstate)
+  IF_NOT_FEATURE_LZMA_FAST(string:)
+ 			do {
+ 				uint32_t pos = buffer_pos - rep0;
+-				if ((int32_t)pos < 0)
++				if ((int32_t)pos < 0) {
+ 					pos += header.dict_size;
++					/* bug 10436 has an example file where this triggers: */
++					if ((int32_t)pos < 0)
++						goto bad;
++				}
+ 				previous_byte = buffer[pos];
+  IF_NOT_FEATURE_LZMA_FAST(one_byte2:)
+ 				buffer[buffer_pos++] = previous_byte;
+-- 
+2.15.1
+